NAME
histo - compute 1-dimensional histogram of N data columns
SYNOPSIS
histo [-c][-p] xmin xmax nbins
histo [-c][-p] imin imax
DESCRIPTION
Histo bins columnular data on the standard input between the given
minimum and maximum values. If three command line arguments are given,
the third is taken as the number of data bins between the first two
real numbers. If only two arguments are given, they are both assumed
to be integers, and the number of data bins will be equal to their
difference plus one. The bins are always of equal size.
The output is N+1 columns of data (for N columns input), where the
first column is the centroid of each division, and each row corresponds
to the frequencies for each column around that value.
If the -c option is present, then histo computes the cumulative
histogram for each column instead of the straight frequencies. The
upper value of each bin is printed also instead of the centroid. This
may be useful in computing percentiles, for example. Values below the
minimum specified are still counted in the cumulative total.
The -p option tells histo to report the percentage of the total number
of input lines rather than the absolute counts. In the case of a
cumulative total, this yeilds the percentile values directly. Values
above the maximum are counted as well as values below in this case.
All input data is interpreted as real values, and columns must be
white-space separated. If any value is less than the minimum or
greater than the maximum, it will be ignored unless the -c option is
specified.
EXAMPLE
To count data values between -1 and 1 in 50 bins:
histo -1 1 50 < input.dat
To count frequencies of integers between 0 and 255:
histo 0 255 < input.dat
AUTHOR
Greg Ward
SEE ALSO
cnt(1), neaten(1), rcalc(1), rlam(1), tabfunc(1), total(1)